[单项选择]

About two percent of the population of the United States is of Asian origin—some five million people. Chinese, Japanese, and Philippines form the largest groups. However, there are also significant numbers of Asian-Indians, Pakistanis, Koreans, and Vietnamese now living in America. As a result of the war in Vietnam, some 350,000 refugees from that country have entered the United States since the early 1970s．
Chinese and Japanese workers were imported into the United States by employers in the late nineteenth and early twentieth centuries．Most of the Chinese settled in California, where they were employed mainly in heavy industries, such as mining and railroad construction. They were faced with intense prejudice and discrimination, especially from lower-class white people, who saw them as a source of threat to their jobs. The retreat of the Chinese into distinct Chinatowns was not primarily their choice, but was enforced by the hostility they faced. Since Chinese imm
A. About 35,000.
B. About 250,000.
C. About 350,000.
D. About 25,000.

[单项选择]

About two percent of the population of the United States is of Asian origin—some five million people. Chinese, Japanese, and Philippines form the largest groups. However, there are also significant numbers of Asian-Indians, Pakistanis, Koreans, and Vietnamese now living in America. As a result of the war in Vietnam, some 350,000 refugees from that country have entered the United States since the early 1970s．
Chinese and Japanese workers were imported into the United States by employers in the late nineteenth and early twentieth centuries．Most of the Chinese settled in California, where they were employed mainly in heavy industries, such as mining and railroad construction. They were faced with intense prejudice and discrimination, especially from lower-class white people, who saw them as a source of threat to their jobs. The retreat of the Chinese into distinct Chinatowns was not primarily their choice, but was enforced by the hostility they faced. Since Chinese imm
A. Because they didn’t understand their language.
B. Because they saw them as a source of threat to their jobs.
C. Because their culture was very different from theirs.
D. Because they had very different appearances.

[填空题]Only about two percent of Antarctica peeks through the thick sheets of ice that blanket the continent. In the winter, the lowest recorded temperatures (without wind chill) have reached -89℃ (-129°F). The continent averages 2.4 kilometers in height (1.5 miles) above sea level, making it 1.5 kilometers (almost a mile) higher than the global average land height! Each year the South Pole receives less than an inch of water...in the form of snow, of course! This amount of precipitation is similar to that of another desert, the Sahara! Katabatic winds, reaching 300 kilometers per hour (185 miles/hour), blow out of the continental interior and make the Antarctic coastal regions rather breezy.
Antarctica is an important part of Earth’s system. By acting as a global heat sink, it helps control our climate and weather. The stability of the Antarctic ice sheets is of concern to those living in low-lying areas; they contain enough water to raise global sea level almost 70 meters.
Ant

[填空题]The world population today is about 6 billion. But only about 11 percent of the world’s land is suitable for farming. However, the area of farmland is becoming smaller and smaller (11) . So it will be difficult to feed so many mouths. There are several reasons why farmland is being (12) . First, a lot of the land is being used for the (13) of houses. Secondly, some of the land has become wasteland because wind and (14) have removed the top soil. Thirdly, some of the land ’has become too salty to (15) . Therefore, a big problem that we face today is hunger.

[填空题]The world population today is about 7 billion. But only about 11 percent of the world’s land is suitable for farming. However, the area of farmland is becoming smaller and smaller (1) . So it will be difficult to feed so many mouths. There are several reasons why farmland is being (2) . First, a lot of land is being used for the (3) of houses. Secondly, some of land has become wasteland because wind and (4) have removed the top soil. Thirdly, some of land has become too salty to (5) . Therefore, a big problem that we face today is hunger.The world population today is about 7 billion. But only about 11 percent of the world’s land is suitable for farming. However, the area of farmland is becoming smaller and smaller (1) . So it will be difficult to feed so many mouths. There are several reasons why farmland is being (2) . First, a lot of land is being used for the (3) of houses. Secondly, some of land has